it works..?

train_leaving.js

// ==UserScript==
// @name         Train leaving
// @namespace    https://gist.github.com/Artoria2e5/8394259c4000f81f9e28
// @updateURL    https://gist.githubusercontent.com/Artoria2e5/8394259c4000f81f9e28/raw/train_leaving.js
// @version      0.3.0
// @description  wuuuuuuuuuuuuuu
// @author       You
// @match        *://www.gtbyxx.com/wxg/station/jyx_station.jsp?code=*
// @match        *://www.gtbyxx.com/wxg/station/crh_station.jsp?code=*
// @match        *://218.29.99.82/WTINFOS/hccx.mor?method=list&station=*
// @grant        Notification
// ==/UserScript==

/* jshint -W097 */
// https://developer.mozilla.org/en-US/docs/Web/API/notification
// http://www.gtbyxx.com/wxg/station/jyx_station.jsp?code=GZZ

// https://stackoverflow.com/a/901144/3770260
function getParameterByName(name, url) {
  if (!url) url = window.location.href;
  name = name.replace(/[\[\]]/g, "\\$&");
  var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
    results = regex.exec(url);
  if (!results) return null;
  if (!results[2]) return '';
  return decodeURIComponent(results[2].replace(/\+/g, " "));
}

// https://stackoverflow.com/a/3067896/3770260
Date.prototype.yyyymmdd = function() {
  var mm = this.getMonth() + 1; // getMonth() is zero-based
  var dd = this.getDate();

  return [this.getFullYear(), (!mm[1] && '0') + mm, (!dd[1] && '0') + dd].join('-'); // padding
};

function DomText(el){ return el ? (el.textContent || el.innerText || '') : ''; }

// fromUTC epoch
var tNow = new Date();
Notification.requestPermission();

if (window.location.hostname === 'www.gtbyxx.com') {
  // 车站代码
  var curr_station_code = getParameterByName("code");
  // 车站名称
  var curr_station_name = DomText(document.querySelector('body > div.nav.nav-bg > h1'));
} else if (window.location.hostname === '218.29.99.82') {
  // 车站代码
  var curr_station_code = getParameterByName("station");
  // 车站名称
  /*                      取文字                          顶上标题           删空格          删掉那几个字 */
  var curr_station_name = DomText(document.querySelector('body > nav > h4')).trim().replace("候车资讯", "");
} else {
  throw new RangeError("Hostname not acceptable.");
}

var trains = window.location.hostname === 'www.gtbyxx.com' ? document.getElementById('trainTable').children :
             window.location.hostname === '218.29.99.82'   ? document.getElementById('infoBody').children   :
             null;

for (var idx = 1; idx < trains.length; ++idx) {
  var train = trains[idx];
  // 也是凑巧，几列排得都一样。。。
  var info = {
    num: DomText(train.children[0]),
    frm: DomText(train.children[1]),
    dst: DomText(train.children[2]),
    time: DomText(train.children[3]),
    // 举一个分情况讨论的例子
    gate: window.location.hostname === 'www.gtbyxx.com' ? DomText(train.children[4]) :
          window.location.hostname === '218.29.99.82'   ? DomText(train.children[5]) : '',
    // 还可以继续取备注 blah..
  };
  // HACK: 手动补一下时间格式
  var t2 = +(Date.parse(window.location.hostname === 'www.gtbyxx.com' ? tNow.getFullYear() + '-' + info.time.replace(' ', 'T') + ':00'  :
                        // HACK: 默认了火车在当天，实际上应该另外扫一圈看有没有折回来（说明是下一天）
                        window.location.hostname === '218.29.99.82'   ? tNow.yyyymmdd() + 'T' + info.time + ':00' :
                        "FAIL")) - 8 * 3600000;
  // 可以有一点提前量……
  if (t2 > (+tNow)) {
      setTimeout(
       (function(info){
          // 前面可以候车地点之类的用过来……
          return new Notification(curr_station_name + '：' + info.num + ' ' + info.frm + '→' + info.dst,
                                  {"body": info.time + ' ' + '你本来写了好多'});
        }),
      t2 - (+tNow),
      info
    );
  }
}